Abstract
Experiments were conducted using porous ceramic inserts to enhance the radiative heat transfer from natural gas flames in a straight-through radiant tube burner. The performance of the radiant tube burner with partially stabilized zirconia and silicon carbide inserts is compared to a baseline case of no inserts at three levels of combustion air preheat. Spectral intensities, temperatures within the radiant tube burner, tube wall temperatures, and exhaust temperatures were measured to determine the effectiveness of the enhanced heat transfer due to the inserts. Exhaust emission constituents were also measured to determine the effect that the inserts have on exhaust products. NOx emissions are reduced by up to 30% with the inserts. The silicon carbide inserts have higher spectral intensities and total radiative energy transfer than partially stabilized zirconia inserts. Both inserts have enhanced radiant heat transfer compared to the no-insert configuration, with the radiative enhancement due to inserts as great as five times that of the no-insert configuration. The net result is increased tube wall temperatures and decreased exhaust temperatures with the ceramic inserts.
Original language | English (US) |
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Pages (from-to) | 848-860 |
Number of pages | 13 |
Journal | Experimental Thermal and Fluid Science |
Volume | 5 |
Issue number | 6 |
DOIs | |
State | Published - Nov 1992 |
Keywords
- porous ceramic inserts
- radiant tube burners
- radiative heat transfer
ASJC Scopus subject areas
- General Chemical Engineering
- Nuclear Energy and Engineering
- Aerospace Engineering
- Mechanical Engineering
- Fluid Flow and Transfer Processes